Add cypress.json schema to Schemastore

[bahmutov]

• write json schema for file cypress.json and submit to https://github.com/SchemaStore/schemastore
• this will provide editors like VSCode, WebStorm, Atom (via https://atom.io/packages/autocomplete-json) with IntelliSense and validation when editing cypress.json file

Example: SchemaStore/schemastore#287

[bahmutov]

Current schema https://github.com/cypress-io/cypress/blob/fd98ccf3c273225fc9ec933c37941cd7c712a2d0/packages/server/lib/scaffold/cypress-schema.json

[bahmutov]

Waiting for pull request SchemaStore/schemastore#384

[bahmutov]

Schema file at https://raw.githubusercontent.com/cypress-io/cypress/develop/cli/schema/cypress.schema.json

[bahmutov]

Docs how to enable in VSCode https://github.com/Microsoft/vscode-tips-and-tricks#add-json-validation

[bahmutov]

My blog post about it https://glebbahmutov.com/blog/json-schema-for-the-win/ using it via user settings and it is working like a charm